Duncan Coutts
On Wed, 2009-08-26 at 18:58 +0100, Jon Fairbairn wrote:
It's not that hard to write
all_spaces xs = checkA (all (isSpace xs)) xs
if that's really what you want.
Not /hard/, but it involves using xs twice, which should tell us something.
I'm not sure it does tell us much,
One thing it tells us is that it's going to be awkward to write in a point-free style.
given that there are also cases where we need to use it only once, and would be forced to use \_ -> to ignore it in the predicate.
The other thing it tells us is that it makes a linear (or should I be saying single-threaded here?) term look like it's not. Using const in the opposite case doesn't have that effect. -- Jón Fairbairn Jon.Fairbairn@cl.cam.ac.uk http://www.chaos.org.uk/~jf/Stuff-I-dont-want.html (updated 2009-01-31)